1. Field of the Invention
The invention relates to an electric door lock, more particularly to an electric door lock with a coupling mechanism for selective engagement between a deadbolt operating spindle and a door handle.
2. Description of the Related Art
A conventional manually operated door lock for locking and unlocking a door panel on a door frame includes a deadbolt, a rotary handle for operating the deadbolt, a latchbolt, and a door knob for operating the latchbolt. The door panel has an inner surface, an outer surface, and a peripheral surface that interconnects the inner and outer surfaces. The door frame is formed with first and second locking grooves. Each of the deadbolt and the latchbolt is adapted to be mounted on the peripheral surface of the door panel. The deadbolt is operable for movement between a locking position, where the deadbolt is extended relative to the peripheral surface of the door panel so as to be adapted to engage the first locking groove in the door frame, and an unlocking position, where the deadbolt is retracted relative to the peripheral surface of the door panel so as to be adapted to disengage from the first locking groove in the door frame. The latchbolt is operable for movement between a latching position, where the latchbolt is extended relative to the peripheral surface of the door panel so as to be adapted to engage the second locking groove in the door frame and retain the door panel in a closed position, and a non-latching position, where the latchbolt is retracted relative to the peripheral surface of the door panel so as to be adapted to disengage from the second locking groove in the door frame and permit opening movement of the door panel.
When one of the deadbolt and the latchbolt is at the respective locking or latching position, operation of the door knob or the rotary handle to move the other of the deadbolt and the latchbolt to the respective unlocking or non-latching position does not permit opening movement of the door panel. In other words, the deadbolt has to be in the unlocking position and the latchbolt has to be in the non-latching position before opening movement of the door panel is possible.
Although the aforementioned conventional door lock achieves the purpose of locking and unlocking the door panel on the door frame, the conventional door lock includes numerous components and requires the deadbolt and the latchbolt to be in proper positions before a door panel can be opened.
Therefore, the object of the present invention is to provide an electric door lock that can overcome the aforesaid drawbacks of the prior art.
According to the present invention, an electric door lock for a door panel comprises a deadbolt, a deadbolt operating spindle, a door handle, and a coupling mechanism. The deadbolt is adapted to be mounted on the door panel and is operable for movement between a locking position, where the deadbolt is extended relative to the door panel, and an unlocking position, where the deadbolt is retracted relative to the door panel. The deadbolt operating spindle is coupled to the deadbolt and is capable of driving movement of the deadbolt between the locking and unlocking positions. The door handle is adapted to be mounted rotatably on the door panel. The coupling mechanism is adapted to be mounted on the door panel, and includes an engaging member, a push unit, and an electric driving motor unit. The engaging member is coupled co-rotatably to the spindle and is axially movable relative to the spindle from a first axial position, where the engaging member can be disengaged from the door handle, to a second axial position, where the engaging member engages the door handle such that rotation of the door handle results in corresponding rotation of the spindle. The push unit, which is driven by the motor unit, is operable so as to move the engaging member from the first axial position to the second axial position.